Bore hole logging apparatus having separate landing member means to position a recording instrument casing above a drill bit



Nov. 26, 1963 J. 0. BE ETT 3,112,442

BORE LE LOGGING APPARATU AVING SEPARATE LANDING ME R MEANS TO POSIT ARECORDING INSTRUMENT CASING ABC RILL BIT Filed Feb 1960 mmvrox JOHN D.BENNETT ATTORNEYS United States Patent 3,112,442 BORE HOLE LOGGINGAPPARATUS HAVHNG SEPARATE LANDING MEMBER MEANS Ti) POSHTIUN A RECORDINGINSTRUMENT CAS- ENG ABQVE A DRILL BET John 1). Bennett, Richardson, Tex,assignor to Sun Gil Company, Philadelphia, Pa, a corporation of NewJersey Filed Feb. 19, 196i), Ser. No. 9,867 6 Claims. (Cl. 3241) Thisinvention relates to bore hole logging apparatus and particularly toapparatus involving the location of recording apparatus within a hole.

Conventional methods of well logging, whether of electrical or othertypes, involve the absence of the drill stem during the loggingoperation. This has two serious drawbacks in that not only must specialtime be consumed in running the well log, during which time the drillstem must be out of the hole, but after a period of drilling, due to thefact that the drill stem must be removed, there is inevitably a delaybefore the new part of the hole may be logged, during which delay thereoccurs invasion of the formation by the drilling liquid. Since thedrilling liquid has physical properties of its own, it may, bypenetration of porous layers, greatly change their properties so as tointerfere with their detection. For example, in the case of electricallogging, the conductivity of the liquid will effect changes in theapparent conductivity of the formations; and in the case of acousticlogging the absorption and velocity of sound will be changed, etc.

Improved logging methods and apparatus are disclosed in the applicationof Fred M. Mayes and Jack Weir Jones, Serial No. 683,027, filedSeptember 10, 1957, now Patent No. 3,065,404, issued November 20, 1962,and the application of John Bennett, Preston E. Chaney, Jack Weir Jonesand Fred M. Mayes, Serial No. 685,717, filed September 23, 1957. Thelogging methods and apparatus so disclosed may be used when a drillstring is in a bore hole and may be used at any time with a minimum ofinterruption in drilling. Not only may the logging be accomplished justprior to removal of the drill string for the purpose of changing a bit,but the logging may be carried out to be promptly followed by acontinuation of drilling. In brief, a self-contained energizing andrecording apparatus may be dropped into a drill string in godevilfashion or may be pumped down therethrough when the drill string hasbeen lifted to only a limited extent from the bottom of the hole toprovide a region for the reception of an electrode or other loggingassembly. The apparatus is of a type suitable to pass through the mudflow opening of a jet bit which may be of any of the conventionalpopular types. Such bits are presently widely used since they effect thecarrying away of cuttings and avoid their reworking by the drill. Thesejet openings are generally at relatively small angles with respect tothe drill stem axis and a flexible electrode assembly may, accordingly,be projected therethrough to extend beneath the bit. For electricallogging the assembly is an electrode assembly; for acoustic or otherlogging it may be of suitable type for exposure to the walls of a hole.

The self-contained assembly which is lowered to the vicinity of the bitcontains, for electrical logging not only means for supplying current tothe earth, but also means for recording various potentials at theelectrodes of the assembly. The recording, as disclosed in saidapplications, may be effected magnetically.

The present invention is directed to apparatus for per mitting thetaking of a log at any time during a drilling operation without removingthe drill stem from the bore hole even though no landing member orsimilar apparatus has been placed in the drill string. The purpose of alanding member is to support and position the self- "ice containedenergizing and recording apparatus in the logging position within thedrill pipe. In accordance with the invention a landing member is loweredinto the drill pipe before the energizing and recording apparatus. Theland ing member is adapted to rest on the drill bit at the bottom of thedrill pipe and provides a landing shoulder at its upper end. As thelogging apparatus is subsequently lowered into the drill pipe, thecasing containing the recording apparatus engages the landing shoulderwhereby the landing member restricts further descent of the loggingapparatus. At this point the logging apparatus will be in the properlogging position.

The object of the invention relates to the attaining of the foregoingresults and will become more apparent from the following descriptionread in conjunction with the accompanying drawing, in which:

FIGURE 1 is an axial sectional view showing, in particular, the approachof the logging apparatus to the lower end of the drill stern comprisinga landing member in accordance with the present invention; and

FTGURE 2 is a section taken on line 22 of FIG- URE 1 shown in anenlarged size.

Details of the apparatus are not shown herein since the recordingelements and the general electrode construction are shown in detail inthe applications referred to above to which reference may be made.Reference may also be had to the application of John D. Bennett, PrestonE. Chaney, Jack Weir Jones, and Fred M. Mayes, Serial No. 813,162, filedJune 4, 1959, for a further description of the electrode and recordingcasing construction. The present invention is concerned primarily withthe external aspects of the apparatus and their relationships to eachother. It will, therefore, be understood that the logging apparatus maycomprise any suitable recording apparatus for electrical or otherlogging and that the electrode assembly may be of any suitable type forthe type of logging which is being carried out. The electrode assemblymay carry electrodes if electrical logging is being performed, or it maycontain acoustic, radioactive, high frequency, or other elements in thecases of other types of logging. For simplicity of description, however,the apparatus will be described as it would be for electrical logging,being of a construction corresponding to that of said priorapplications.

A conventional hollow drill stem is indicated at 2. This drill stemcomprises at its lower end the usual drill collar 4 carrying the bit 5provided with mud flow openings 6 desirably lined, as usual, witherosion-resisting liners 8.

A casing 10* contains a recording apparatus 11 which is preferably ofthe type disclosed in said application Serial No. 818,162. The upper endof casing 10 is con nected to apparatus, such as that disclosed in saidlastmentioned application, for restraining the rate of descent of thecasing it? through the drill collar 4-. Extending from the lower end ofcasing it! is a flexible electrode assembly 12.

The electrode assembly 12, which is preferably of the type more fullydisclosed in said application Serial No. 818,162, is fundamentally amulticonductor insulated electrical cable on which electrodes areprovided. Any number of electrodes may be provided as indicated at 13and 14- each being connected to an individual conductor of the cable. Atthe lower end of the electrode assembly 12 there is a Weightingarrangement 15 having a sufiicient number of Weights to insure that,during lowering, the flexible electrode assembly 12 will remain undertension. The arrangement just described provides the necessaryflexibility to enable the entire assembly to pass through a jet opening.A flexible strip 16 of leather or plastic extends from the weightingarrangement 15 and facilitates, by its entrainment in the drilling mudflow,

the guidance of the electrode assembly into a jet opening. Thearrangement is such that ultimately the electrode assembly 12 isprojected through the drill bit so that the electrodes exposed to thewalls of the hole below the bit with adequate spacing from the bit so asto provide the desired electrical configuration.

Casing is provided with a landing ring 18 at the lower end thereof. Ringhas a conical seating surface 2% forming the lowermost end of easingIll). Within the ring 13 there are mounted pins 2 1 projecting slightlybeyond the conical surface Ztl of the ring 18. These pins areelectrically connected to each other and to the recording apparatus forgrounding the latter as will hereinafter be described.

Means are provided for positioning the recording apparatus at the end ofits descent into the drill collar Such means comprises a landing member22 including a hollow cylindrical portion 24 having outer wall 2-6substantially concentric with the internal wall of the drill collar 4but having a slightly smaller diameter whereby the landing member 22 iscentrally positioned. While there should be a sung fit between portion24 and the internal wall of the drill collar 4, there must be sufficientfreedom to permit entrance of the landing member 22.

The lower end of the cylindrical portion 24 is joined with three rods 23ci cumferentially spaced at their upper ends about cylindrical portion24 and joined at their lower ends to form a spider arrangement. Anotherrod is joined to the lower ends of rods 23 and extends downwardlytherefrom. Rod 30 has an enlarged head 32 at the lower end thereofadapted to engage the usual interior shoulder 34- of drill bit 5 wherebythe landing member 22 is adapted to rest on the drill bit 5 in adefinite vertical relationship thereto. The upper end of cylindricalportion is provided with a conical shoulder 3t: adapted to be engaged bythe conical surface 28 of casing 19. When casing 10 is seated on theconical shoulder 36, pointed ends of pins 21 are forced into the seat 36to provide the necessary electrical contact, penetrating scale or otherresistant material which mav accumulate on the seat 36. The bottom ofthe head 32 of landing member 22 may also be provided with sharpprojections for insuring good electrical contact with the shoulder 24 ofthe drill bit 5. Hence, there is an effective grounding of the recordingapparatus through the landing member 22.

A ring 38 of suitable sealing material, such as neoprcne, is containedwithin an annular recess 40 at the outer diameter of the upper end ofcylindrical portion 24 to provide a protective seal with the internalwall of the drill collar 4. This seal restricts the flow of drilling mudbetween the wall 26 and the internal wall of the drill collar 4- tothereby prevent abrasion of such walls by the drilling mud. Spaced rods28 define a plurality of openings 42 to permit the passage of electrodeassembly 12 through the landing member 22 and are rounded to guide orcam a descending electrode assembly 12 through the opening 42.

In operation, if it is desired to log a hole and no landing member hasbeen placed in the drill stem before the drill pipe was run into thehole, the drill stem is raised from the bottom of the hole to provide aspace for the extension of the electrode assembly 12 below the bit 5. Ifthe exact size of the inner diameter of the drill collar 4 is not known,this dimension may be measured by a calipering device of a well-knowntype which may be lowered into the drill bore on a line and retrieved. Alanding member 22 of a diameter slightly less than the diameter of thedrill collar bore is then dropped into or pumped down from the top andcomes to rest in the position shown in FIGURE 1 upon engagement of rod30 with bit 5. Next the recording assembly is dropped in go-devilfashion, lowered on a Wire line or pumped down through the drill stem.Reference is made to said 4 application, Serial No. 818,162 for thedetails of the lowering of the recording assembly.

As the recording assembly moves downwardly, the electrode assembly 12passes through the hollow cyclindrical portion 24 and one of theopenings 42 of landing member 22 and then enters and feeds through a jetOpening in the bit. The extension rod 3% serves to space the body of thelanding member 22 from shoulder 34 to insure that the jet openings 6will not be covered and to give the flexible electrode assembly 12freedom of movement after it passes the arms 28 to adjust itself forentrance into a jet opening. The recording assembly comes to rest uponengagement by the conical surface 20 of casing 10 with shoulder 26 oflanding member 22 and with the electrode assembly 12 fully extended. Thelogging op- -ration may then be carried out with the apparatus seated onthe landing member 22. Since the position of the drill bit 5 is knownand the landing member 22 positions the recording apparatus in a knownvertical position relative to the drill bit, the position of theelectrodes may be readily determined.

The actual logging operation after the assembly is located at the bottomof the drill stem is carried out in the fashion described in said priorapplications, provisions being made to start the recording andenergizing apparatus, the drill stem being lifted for logging purposesto the desired extent. Finally the logging apparatus may be removed byan overshot lowered on a wire line or may be recovered when the drillbit is brought to the surface.

It will be evident that the features of the invention may be carried outby other apparatus, and it is therefore to be understood that theinvention is not limited except as required by the following claims.

What is claimed is:

1. Bore hole logging apparatus for use in a drill stem having an axialbore therethrough comprising a casing containing recording apparatus,said casing having a construction and shape such that it fits within theaxial bore of the drill stem for lowering of said casing therethrough, adrill bit carried by the drill stem, and means separate from said casingand drill stem arranged to be lowered through the drill stemindependently of said casing to rest on said drill bit and providing alanding shoulder spaced above said drill bit for positioning said casingfor the logging operation.

2. Bore hole logging appaartus for use in a drill stem having an axialbore therethrough comprising a casing containing recording apparatus,said casing having a construction and shape such that it fits within theaxial bore of the drill stern for lowering of said casing therethrough,a flexible member extending from the bottom of said casing, a drill bitcarried by the drill stern and having an opening through which saidflexible member may project to extend below said bit when said casing isin the position for logging, and means arranged to be lowered throughthe drill stem to rest on said bit and providing a landing shoulder forpositioning said casing for the logging operation and an opening throughwhich said flexible member projects when said casing rests on saidshoulder.

3. Apparatus as claimed in claim 2 wherein said positioning meanscomprises a wall portion substantially concentric with the walls of thedrill stem bore for centrally disposing said positioning means thereinand a member joined with said wall portion extending downwardlytherefrom for contact with said bit.

4. Apparatus as claimed in claim 3 wherein said wall portion definessaid landing shoulder at the upper end thereof and said means joiningsaid last named member to said wall port-ion comprises a plurality ofspaced arms positioning said last named member centrally of said wallmember.

5. A landing member for positioning bore hole logging apparatus at thelower end of a drill stem having an axial bore therethrough and a drillbit at the lower end thereof,

said landing member being a separate structure unconnected to saidlogging apparatus or said drill stem and comprising a wall portionsubstantially concentric with the wall of the drill stem bore tocentrally position the landing member within the bore, said wall portionhaving a landing shoulder at the upper end thereof for contacting borehole logging apparatus descending through said drill stem to arrest thesame upon contact with said shoulder, said wall portion having a smallerconfiguration than the drill stem bore for lowering thereof through thedrill stem, a member extending downwardly from and joined to said wallportion, said member being arranged to contact at the lower end thereofa drill bit carried by the drill stem to space said 'wall portion fromthe drill bit, and means defining a passageway through said Wall portionand said member.

6. A landing member for positioning bore hole logging apparatus at thelower end of a drill stem having an axial bore therethrough and a drillbit at the lower end thereof, said landing member being a separatestructure in itself and comprising a tubular wall portion substantiallyconcentric with the wall of the drill stem bore to centrally positionthe landing member within the bore, said wall portion having a landingshoulder at the upper end thereof for contact by bore hole loggingapparatus, said wall portion having a smaller configuration than thedrill stem bore for lowering thereof through the drill stem, a memberextending downwardly from and joined to said wall portion, said memberincluding a rod and spider means joining said rod and said wall portion,said rod being contactable at the lower end thereof with a drill bitcarried by the drill stem to space said wall portion from the drill bit,and means defining a passageway through said wall portion and saidmember, said passageway being defined by the interior of said wallportion and by said spider means.

References Cited in the file of this patent UNITED STATES PATENTS2,070,912 McDermott Feb. 16, 1937 2,337,269 Piety Dec. 21, 19432,344,598 Church Mar. 21, 1944 2,349,366 Moon May 23, 1944 2,370,818Silverman Mar. 6, 1945 2,650,067 Martin Aug. 25, 1953 2,759,143 ArpsAug. 14, 1956 2,779,915 Moon Jan. 29, 1957

1. BORE HOLE LOGGING APPARATUS FOR USE IN A DRILL STEM HAVING AN AXIALBORE THERETHROUGH COMPRISING A CASING CONTAINING RECORDING APPARATUS,SAID CASING HAVING A CONSTRUCTION AND SHAPE SUCH THAT IT FITS WITHIN THEAXIAL BORE OF THE DRILL STEM FOR LOWERING OF SAID CASING THERETHROUGH, ADRILL BIT CARRIED BY THE DRILL STEM, AND MEANS SEPARATE FROM SAID CASINGAND DRILL STEM ARRANGED TO BE LOWERED THROUGH THE DRILL STEMINDEPENDENTLY OF SAID CASING TO REST ON SAID DRILL BIT AND PROVIDING ALANDING SHOUL-